1. Technical Field
The present disclosure relates to a platen device that applies suction to a conveyed recording medium, and to a printer having the platen device.
2. Related Art
One example of such a platen device is a suction platen mechanism disposed opposite the inkjet head in an inkjet roll paper printer such as described in JP-A-2010-201683.
This suction platen mechanism has a platen surface opposite the inkjet head, and a suction mechanism that holds recording paper conveyed over the platen surface against the platen surface by suction. The platen surface has a first suction zone substantially in the center of the transverse (widthwise) direction perpendicular to the conveyance direction of the recording paper, and two second suction zones on opposite sides of the first suction zone. The first suction zone and second suction zones are separated by ribs on the platen surface, and the second suction zones are further divided by a plurality of ribs into multiple subzones. A checkerboard grid of suction holes that communicate with a suction fan is formed in the first suction zone, and a suction hole formed in each of the subzones also communicates with the suction fan. Air can therefore be prevented from leaking from the sides of narrow recording paper, and the sides of wide recording paper can be prevented from lifting away from the platen surface.
To prevent air leakage when using narrow recording paper, this suction platen mechanism of the related art is designed so that suction is weaker in the second suction zones than in the first suction zone. As a result, thick paper that tends to curl at the sides of the width may be conveyed (printed) without this curling being removed due to insufficient suction in the second suction zones.
When printing on synthetic label paper having a plastic film with an adhesive backing carried on a paper liner, for example, the liner can absorb moisture (swell) and curl at the sides of the paper width under high temperature, high humidity conditions. Problems can then occur when the recording paper is conveyed over the platen surface with curled edges, including a drop in print quality because a desirable paper gap cannot be maintained, or the recording paper interfering with the inkjet head.